Applicant's prior patents and particularly his U.S. Pat. No. 2,750,901 discloses generally one type of an insulated filing cabinet including a plurality of latches and locking means having functions similar to those of the present invention. Besides what is disclosed in this McClellan patent, metallic shells having panels connected in U-shaped pieces are also known in
______________________________________ Schriefer 1,294,838 February 18, 1919 Class 109-58 Walker 1,543,349 June 23, 1925 ______________________________________
and Schriefer also shows reverse bend edges flanges as does
______________________________________ Gibson et al 2,148,689 February 28, 1939 Class 109-82 ______________________________________
The use of adhesives instead of welding for assembly of the sheet metal parts is taught by
______________________________________ Schreyer 3,391,967 July 9, 1968 Class 312-256 ______________________________________
and insulation containing glass fibers is taught in
______________________________________ Ganger et al 3,709,169 January 9, 1973 Class 109-29 Noone 3,916,804 November 4, 1975 Class 109-78 ______________________________________
Drawers for such filing cabinets having insulated front panels or doors that are easily moved therefrom are also shown in the above mentioned McClellan patent, and movable dividers and followers for the drawers are shown in
______________________________________ Macrae 590,666 September 28, 1897 Class 220-22.5 Schmidt 1,163,373 December 7, 1915 Class 220-22.3 Rand 1,948,935 February 27, 1934 Class 220-22.4 Budai 2,507,366 May 9, 1950 Murray 3,281,193 October 25, 1966 Class 211-46 ______________________________________
The above mentioned McClellan U.S. Pat. No. 2,750,901 also discloses several different combinations of locking and latching means of the doors to drawers of filing cabinets, including a twist handle latch, a key plunger lock cooperating with a combination lock and vertically movable locking bar along both sides of the inner shell for gang locking and interlocking other drawers of the cabinet simultaneously. A pull handle for such cabinet drawers is shown also in the above mentioned Schreyer U.S. Pat. No. 3,391,967 and in
______________________________________ Eland-Mantle 2,427,386 September 16, 1947 Class 70-208 ______________________________________
and a resettable combination lock is also shown in
______________________________________ Ashton 1,801,299 April 21, 1931 Class 70-314 ______________________________________
In addition to means for simultaneously locking all of the drawers by a lock on a single drawer, there is also known means for interlocking the drawers so that more than one drawer cannot be opened at a time as shown in
______________________________________ Latham 3,883,200 May 13, 1975 Class 312-216 Klenik, Jr. et al 3,957,324 May 18, 1976 Class 312-218 ______________________________________
Although many of the features of the present invention are broadly disclosed in the above mentioned patents, many of the improved features of the present invention are not disclosed, taught or predicted thereby, including the specific combination of the features of this invention, such as the reduction in the number of parts and welds required, the structure and shape of the shell edge flanges, the employment of antifriction plastic parts for the door latches and follower slides, the easy interchangeability between pull and rotary door handles for operating the same latching mechanism, additional rail means for guiding drawers particularly for lateral or wide-drawer filing cabinets to maintain their alignment and prevent skewing, the adaptability of the locking levers and plungers for each drawer operated by a vertical locking bar so that the drawers can be interlocked and locked or not locked as desired by installation or removal of common standard plates having all the cooperating levers and plungers mounted thereon, and still other new and advantageous features described in the following description.